June 24, 2014

Previous studies have found that people who use marijuana, especially starting young and for extended periods, are roughly twice as likely to develop schizophrenia as pot abstainers, but new research indicates that while pot may cause schizophrenia, the reverse is also true. The study, by the Institute of Psychiatry at King's College London, included more than 1,000 pot users, and found that the more genes an individual carried that were related to schizophrenia, the more likely they were to use marijuana, and in greater amounts, than those with few or no schizophrenia risk genes. The researchers concluded that the "causality" between the drug and the mental disorder runs a both ways, and that a common group of genes predispose carriers to both the disorder and the drug.